The Labour Party conference in Christchurch this weekend looks set to approve a remit that will require its list to "fairly represent" gays and lesbians among candidates.

At present, the constitution says there shall be no barriers to nominees on the grounds of sexual orientation or marital status. But a remit proposed by the party's ruling New Zealand Council would require the list-ranking committee to pro-actively ensure that its list fairly represents "sexual orientations", as well as tangata whenua, gender, ethnic groups, people with disabilities, age and youth.

The New Zealand Council is also proposing a Maori-only list ranking committee to rank its Maori candidates for the next election.

Under another remit, Labour's list-ranking committee decisions will also have to aim for a caucus of at least 45 per cent of women next year and at least 50 per cent in 2017. That target was foreshadowed earlier this year when former leader David Shearer ditched the controversial so-called "man-ban" remit, which would have allowed for women-only selections in some electorates.

Debates on the constitutional issues this weekend will be held in closed session, after a very public row last year on how to trigger a leadership vote that pitted many MPs against members.

Labour general secretary and former MP Tim Barnett told the Herald yesterday the proposed rule change around sexual orientation reflected changing views. When he had been elected as MP for Christchurch Central in 1996, he was the first openly gay candidate elected to a seat.

"And within quite a short period [that changed] to a situation where a caucus not containing their representatives would be considered probably not meeting the kind of diversity we are looking for. A caucus not containing women, or Maori, or Pacific people or people from ethnic minorities, I think that reflects the shifting of the debate in that area." Among the present caucus of 34 Labour MPs, four are known to be gay: Grant Robertson, Maryan Street, Louisa Wall, and Meka Whaitiri.

Mr Barnett said that after last year's experience, it was felt that holding the debate in closed session would allow members to "be passionate about stuff which is internal, which is really about how we keep our own house in order or get it into order".

Debate on policy remits will also be held in private although debate about its new "Policy Platform," a statement of values, would be held in open session.